Troy Polamalu's sore right shoulder has come a long way the past two or three weeks -- just in time for what should be his biggest challenge to date this season, San Diego tight end Antonio Gates.

Whomever gets the best of that matchup could determine whether the Steelers or Chargers win tonight. For Polamalu, though, Gates is just another in a long line of nimble, tall, muscular receivers misidentified as "tight ends" that flourish throughout the NFL.

"To tell you the truth," Polamalu said, "I don't think he's any harder to cover than any of the other tight ends. The reason I say that is there are great tight ends all over the place."

After Gates tonight, there's no break for Polamalu. Next Sunday he has Kansas City's Tony Gonzalez. The week after that, it's Alge Crumpler in Atlanta. And that's not the end of it. Baltimore's Todd Heap and Cleveland's Kellen Winslow Jr. appear on the schedule twice each.

"We have three All-Pro tight ends just in our division," Polamalu noted.

He meant All-Pro caliber, and at least he does not have to cover one of them outside of his own practice sessions. Heath Miller, who caught 39 passes and six for touchdowns as a rookie with the Steelers last year, has quickly joined the group.

It's rare when a team does not have such a big target to split out wide or bring in tight to cause defensive coaches and players nightmares.

"The past few years, teams recognized that was a big part of the game," said Tom Modrak, the Buffalo Bills' assistant general manager who has scouted colleges for more than 30 years. "With the Cover 2 defense, the schemes and everything, those kinds of guys help counter what the defense is doing. It gives you one more way of getting the ball down the field, putting more speed on the field if you can get that kind of guy."

Gates ranked second in the AFC with 89 receptions last season, tying Winslow's daddy for the franchise record by a tight end. Gonzalez caught 78 for the Chiefs, Heap 75 for the Ravens and Crumpler 65 for the Falcons. Randy McMichael, covered by Polamalu in the season opener, caught 60 passes for Miami last season. Polamalu this season won't have to cover Jason Witten, who caught 66 passes for the Cowboys last year, and the Giants' Jeremy Shockey, who caught 65.

There have been tight ends of their ilk before in the league, such as Winslow Sr., Ozzie Newsome, Shannon Sharpe, but never have so many big, athletic tight ends caught so many passes as they are doing in the NFL of the 21st century.

They're all in the same range, 6 feet 3 to 6-5 and weighing 255 or so.

"Everyone's looking for that type of athlete at that position because it's such a difference-maker," Steelers cornerback Deshea Townsend said.

But with the proliferation of the receiving tight end, more and more guys like Townsend must cover them. No longer do they just line up "tight" and next to a tackle. Even Miller, who is called on to block more often than most of them, has lined up wide like Hines Ward, and in the slot, on the wing, in the backfield and sent in motion. The Chargers do not hesitate to send Gates on a "go" route or a post pattern.

"He runs every route, the same routes as the other guys," Townsend said. "That's the type of athlete he is. "

Gates goes 6-4, 260. Townsend is 5-10, 190. Even Polamalu, at 5-10, 207, is at quite a physical disadvantage against Gates.

Steelers backup quarterback Charlie Batch took advantage of the Steelers' own mismatch when he completed three passes to the 6-5, 256-pound Miller in the opener, one for an 87-yard touchdown. Batch believes that kind of tight end is nearly impossible to stop. Plus, he serves as a security blanket when a quarterback gets under a heavy rush.

"That's something you always look for," Batch said. "When you think you need 4 or 5 yards, he's going to get it every single time. He should be able to win that matchup every time. "

One way to counter them is with a good strong safety, like the Steelers have with Polamalu. The proliferation of the big, athletic tight ends have been good business for strong safeties.

"Not that safeties weren't always important," Modrak said, "but there's an evolution there because of the tight ends. Maybe, they've become more important. You'd see safeties relegated to the second and third rounds in the draft. Now they're higher. You have to have guys who can run and cover and not just play in the box, a lot of it because of the new breed of tight ends like Gates."

They're a new breed who need a new name because tight end just does not fit.